### 1. **Using `xrandr`**
`xrandr` (X Resize and Rotate) is a command-line tool that allows you to change display settings, including resolution.
#### Steps:
1. Open a terminal.
2. List the available resolutions for your HDMI screen:
```bash
xrandr
```
Look for your HDMI screen in the output (e.g., `HDMI-1` or `HDMI-2`).
3. Add the desired resolution if it's not listed. For example, to add 1920x1080:
```bash
xrandr --newmode "1920x1080_60.00" 173.00 1920 2048 2248 2576 1080 1083 1088 1120 -hsync +vsync
xrandr --addmode HDMI-1 "1920x1080_60.00"
```
Replace `HDMI-1` with the name of your HDMI screen.
4. Set the new resolution:
```bash
xrandr --output HDMI-1 --mode "1920x1080_60.00"
```
5. To make this change permanent, add the commands to your startup scripts or `.xprofile` file.
### 2. **Using `arandr` (GUI Tool)**
`arandr` is a graphical frontend for `xrandr` that makes it easier to configure display settings.
#### Steps:
1. Install `arandr`:
```bash
sudo apt install arandr
```
2. Run `arandr`:
```bash
arandr
```
3. In the GUI, select your HDMI screen and choose the desired resolution from the dropdown menu.
4. Click "Apply" to set the resolution.
### 3. **Using `cvt` and `xrandr` Together**
If the desired resolution is not listed, you can generate a modeline using `cvt` and then add it with `xrandr`.
#### Steps:
1. Generate a modeline for the desired resolution (e.g., 1920x1080):
```bash
cvt 1920 1080
```
This will output a modeline like:
```
Modeline "1920x1080_60.00" 173.00 1920 2048 2248 2576 1080 1083 1088 1120 -hsync +vsync
```
2. Add the new mode:
```bash
xrandr --newmode "1920x1080_60.00" 173.00 1920 2048 2248 2576 1080 1083 1088 1120 -hsync +vsync
xrandr --addmode HDMI-1 "1920x1080_60.00"
```
3. Set the new resolution:
```bash
xrandr --output HDMI-1 --mode "1920x1080_60.00"
```
### 4. **Using Display Settings in Your Desktop Environment**
If you're using a desktop environment like GNOME, KDE, or XFCE, you can often change the resolution through the system settings.
#### Steps:
1. Open the system settings or display settings application.
2. Navigate to the display section.
3. Select your HDMI screen and choose the desired resolution from the list.
4. Apply the changes.
### 5. **Editing Xorg Configuration File**
For a more permanent solution, you can edit the Xorg configuration file.
#### Steps:
1. Create or edit the Xorg configuration file:
```bash
sudo nano /etc/X11/xorg.conf
```
2. Add a section for your HDMI screen with the desired resolution. For example:
```plaintext
Section "Monitor"
Identifier "HDMI-1"
Modeline "1920x1080_60.00" 173.00 1920 2048 2248 2576 1080 1083 1088 1120 -hsync +vsync
Option "PreferredMode" "1920x1080_60.00"
EndSection
Section "Screen"
Identifier "Screen0"
Monitor "HDMI-1"
DefaultDepth 24
SubSection "Display"
Modes "1920x1080_60.00"
EndSubSection
EndSection
```
3. Save the file and restart your display manager or reboot your system.
### Conclusion
The easiest method is usually using `xrandr` or `arandr`. If you prefer a graphical interface, `arandr` is a great choice. For a more permanent
solution, editing the Xorg configuration file or using your desktop environment's display settings can be helpful.